योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-210, verse-34

लोके शास्त्रेऽथ वेदादौ यत्सिद्धं सिद्धमेव तत् ।
सदस्त्वसद्वात्मनि तद्धातुं शक्यं न वा क्वचित् ॥ ३४ ॥

loke śāstre'tha vedādau yatsiddhaṃ siddhameva tat ,
sadastvasadvātmani taddhātuṃ śakyaṃ na vā kvacit 34

34. The joint assent of the common belief of mankind, the testimony of the sastras, and the dicta of the Vedas, are established and incontrovertible truths. Hence nobody can have any doubt in regard to the real entity of the Divine spirit.